Electronic Rev Counter Wiring

Here's an easy one for you electrickery types Which wire is which here coz i'm not that clued up

 

A guess based on the fact that the blob at the top is probably a backlighting bulb holder cover .. but a guess.

Eye terminal black : to Ground
Spade with red/grey and black/white : probably headlamp /dash lighting
Red : Ignition +
Blue : Ignition coil

 

Thanks Iv'e just bought it off fleabay and i'm now just hoping it's gonna be ok , 80mm so it'll go in the spare dash pod hole